I have a community with a lot of tags, not all of which get used right away. This means that users can't see these tags until notified OR if I maintain a post like this one where I add every new tag after creation to make it visible to members. So either being able to pick the security level upon creation (or some sort of journal default option of "make all tags public") would be really nice, otherwise while it's a good idea the implementation isn't very versatile.